tests/cogl: Migrate texture rg test

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2555>

src/tests/cogl/conform/meson.build

@@ -37,6 +37,7 @@ cogl_tests = [
   [ 'test-pipeline-cache-unrefs-texture', [] ],
   [ 'test-texture-no-allocate', [] ],
   [ 'test-pipeline-shader-state', [] ],
+  [ 'test-texture-rg', [] ],
 ]
 
 cogl_test_conformance_includes = [

src/tests/cogl/conform/test-texture-rg.c

@@ -0,0 +1,84 @@
+#include <cogl/cogl.h>
+
+#include <string.h>
+
+#include "tests/cogl-test-utils.h"
+
+#define TEX_WIDTH 8
+#define TEX_HEIGHT 8
+
+static CoglTexture2D *
+make_texture (void)
+{
+  uint8_t tex_data[TEX_WIDTH * TEX_HEIGHT * 2], *p = tex_data;
+  int x, y;
+
+  for (y = 0; y < TEX_HEIGHT; y++)
+    for (x = 0; x < TEX_WIDTH; x++)
+      {
+        *(p++) = x * 256 / TEX_WIDTH;
+        *(p++) = y * 256 / TEX_HEIGHT;
+      }
+
+  return cogl_texture_2d_new_from_data (test_ctx,
+                                        TEX_WIDTH, TEX_HEIGHT,
+                                        COGL_PIXEL_FORMAT_RG_88,
+                                        TEX_WIDTH * 2,
+                                        tex_data,
+                                        NULL);
+}
+
+static void
+test_texture_rg (void)
+{
+  CoglPipeline *pipeline;
+  CoglTexture2D *tex;
+  int fb_width, fb_height;
+  int x, y;
+
+  if (!cogl_has_feature (test_ctx, COGL_FEATURE_ID_TEXTURE_RG))
+    {
+      g_test_skip ("Missing TEXTURE_RG feature");
+      return;
+    }
+
+  fb_width = cogl_framebuffer_get_width (test_fb);
+  fb_height = cogl_framebuffer_get_height (test_fb);
+
+  tex = make_texture ();
+
+  g_assert (cogl_texture_get_components (tex) == COGL_TEXTURE_COMPONENTS_RG);
+
+  pipeline = cogl_pipeline_new (test_ctx);
+
+  cogl_pipeline_set_layer_texture (pipeline, 0, tex);
+  cogl_pipeline_set_layer_filters (pipeline,
+                                   0,
+                                   COGL_PIPELINE_FILTER_NEAREST,
+                                   COGL_PIPELINE_FILTER_NEAREST);
+
+  cogl_framebuffer_draw_rectangle (test_fb,
+                                   pipeline,
+                                   -1.0f, 1.0f,
+                                   1.0f, -1.0f);
+
+  for (y = 0; y < TEX_HEIGHT; y++)
+    for (x = 0; x < TEX_WIDTH; x++)
+      {
+        test_utils_check_pixel_rgb (test_fb,
+                                    x * fb_width / TEX_WIDTH +
+                                    fb_width / (TEX_WIDTH * 2),
+                                    y * fb_height / TEX_HEIGHT +
+                                    fb_height / (TEX_HEIGHT * 2),
+                                    x * 256 / TEX_WIDTH,
+                                    y * 256 / TEX_HEIGHT,
+                                    0);
+      }
+
+  cogl_object_unref (pipeline);
+  cogl_object_unref (tex);
+}
+
+COGL_TEST_SUITE (
+  g_test_add_func ("/texture/rg", test_texture_rg);
+)